Pre-slit injection site and tapered cannula

ABSTRACT

A pre-slit injection site includes a housing with a flow path therethrough. A first end of the housing carries a pre-slit septum. One form of a blunt cannula, usable with the injection site, carries a locking member. When the pre-slit injection site slidably receives the blunt cannula, the locking member latches to the injection site and creates a mechanically coupled unit. Another form of the cannula includes a tube having a tapered distal end region and having elongate discharge slots for reducing contact surface area and for directing the flow laterally out of the cannula. The cannula may also include a rounded lead post, an annular barb, and axially oriented grooves.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 08/470,380 filed on Jun.6, 1995, U.S. Pat 5,797,897, which is a continuation in part ofapplication Ser. No. 08/183,110, filed Jan. 18, 1994 now abandoned,which is a continuation in part of application Ser. No. 639,773 Jan. 10,1991 now abandoned, which is a continuation of application Ser. No.217,004 filed Jul. 8, 1988 now abandoned, which is acontinuation-in-part of application Ser. No. 147,414, filed Jan. 25,1988 now abandoned.

FIELD OF THE INVENTION

The invention pertains to coupling systems usable to transfer materialsfrom one flow conduit to another. More particularly, the inventionpertains to two-part coupling members with a first part including apre-slit septum and a second part including a blunt cannula. Thepre-slit septum slidably receives the blunt cannula to effect thecoupling.

BACKGROUND OF THE INVENTION

Injection sites usable with pointed cannulae have long been known. Forexample, such sites can be formed with a housing having a fluid flowpath therein. A septum is positioned in the housing closing the fluidflow path.

One injection site usable with a piercing cannula is disclosed in U.S.Pat. No. 4,412,573 to Zdeb entitled "Injection Site." The Zdeb patent isassigned to the assignee of the present invention.

The pointed cannula can be forced through the septum into fluid flowcommunication with the flow path in the housing. Known injection sitesusable with a piercing cannula can be physically damaged by repetitivepiercing caused by the sharp cannula. This damage, known as coring orlaceration, can result in subsequent leakage.

Due to problems associated with infectious agents, personnel using suchpointed cannulae do so with great care. Notwithstanding careful andprudent practice, from time to time, accidents do occur and individualsusing such pointed cannulae jab themselves.

Injection sites usable with a blunt cannula are also known. For example,U.S. Pat. No. 4,197,848 issued to Garrett et al. entitled "ClosedUrinary Irrigation Site" and assigned to the assignee of the presentinvention discloses one such injection site. That injection site is arelatively low pressure device having a relatively thin, molded, sealingmember. The sealing member has an opening therethrough.

A blunt cannulae can be forced through the sealing member placing thecannulae into fluid flow communication with a fluid flow pathway in theinjection site.

Injection sites of the type noted above usable with a blunt cannula havethe advantage that the blunt cannula will not pierce the skin of a user.On the other hand, it is important that the pre-slit injection sitereseal with enough force that fluids do not ooze therefrom and thatairborne particulate matter, bacterial or viral matter do not entertherethrough.

Hence, there continues to be a need for a pre-slit injection site whichcan be used with a variety of solutions and over a range of fluidpressures. Further, there continues to be a need for such a pre-slitinjection site which will reliably reseal even after many insertions ofthe blunt cannula.

Such an injection site should be able to receive a large number ofinsertions of the cannula without displaying reseal failure. Such aninjection site should provide for improved alignment of the cannula oninsertion. Improved alignment will result in less chance of damage tothe injection site after repeated insertions of the cannula. Preferably,the injection site would also be usable with a pointed cannula.Preferably, a pre-slit injection site usable with a blunt cannula willprovide a reasonable level of insertion force such that health carepersonnel will readily be able to insert the blunt cannula, yet thecannula will not easily fall from or drop out of contact with theseptum.

SUMMARY OF THE INVENTION

In accordance with the invention, an easily wipeable injection siteusable with a blunt cannula is provided. The injection site includes ahousing which defines a fluid flow channel therethrough. The housing hasa first and a second end.

A flexible sealing member is carried by the housing for sealing thefirst end. The sealing member has a resealable opening therein. Thesealing member also is formed with a curved exterior peripheral surfacesuch that the blunt cannula can be sealingly inserted through theopening and placed in fluid flow communication with the flow path.Further, the blunt cannula can be removed from the opening with thesealing member then interacting with the housing so as to reseal theopening.

The housing can also be formed with the first end including an annularchannel underlying the sealing member. The sealing member is subjectedto radially directed forces by a tapered surface of the first end of thehousing. These forces tend to reseal the opening in the sealing member.

The sealing member can be a cylindrically shaped rubber member. Thefirst end of the housing can include an interior tapered surface forreceiving the sealing member and for applying the radially directedforces to the sealing member.

A retaining member carried by the first end of the housing can be usedto retain the sealing member within the housing. The retaining membercan be generally U-shaped. Alternately, the retaining member can beformed as a coiled spring.

The retaining member applies axially directed forces to the sealingmember. In one embodiment of the invention, the retaining memberdeflects the sealing member and forms a curved exterior peripheralsurface thereon. The curved exterior peripheral surface is an easilywipeable surface.

The retaining member deflects or distorts the upper and lower peripheraledges slightly as a result of applying axial forces thereto. When theblunt cannula is inserted into the slit in the sealing member, anannular interior peripheral region of the sealing member deforms furtherand fills, at least in part, the annular channel.

Deformation of this annular peripheral region results in an insertionforce in a range of 2.0 to 5 pounds. Preferably, the insertion forcewill have a value of the order of 2.0 pounds.

The resealable opening in the sealing member can extend entirely throughthat member. Alternately, the resealable opening can extend only partwaytherethrough. In this embodiment, the end of the blunt cannula will beused to tear through the remainder of the sealing member.

The sealing member can be formed in two parts. An exterior cylindricalportion can be slit completely. An interior cylindrical unslit portioncan be provided to seal the site until the blunt cannula is insertedtherethrough the first time.

The interior surface of the first end can be formed with the taper in arange on the order of 5 degrees to 20 degrees. Preferably, the interiorsurface will have a taper on the order of 12 degrees. This taperedsurface permits the use of a cylindrically shaped sealing member.

To provide for leak-free insertion, the length of the slit in thesealing member must be less than one-half the circumference of thecannula being inserted therethrough. Hence, the slit length may exceedthe diameter of the cannula being inserted. In addition, the slit lengthmust be great enough, given the elastic limit of the sealing member, toprevent tearing during insertion.

Further in accordance with the invention, a coupling system for couplingfirst and second fluid flow members together is provided. The couplingsystem includes an injection site which is affixed to the first fluidflow member. The injection site includes a housing. The housing has afluid flow path therethrough.

A sealing member is carried by the housing. The sealing member has aresealable opening therein.

An annular retaining member is carried by the housing and cooperateswith the housing to retain the sealing member therein. Radially directedforces are applied to the sealing member by the housing, thereby urgingthe opening into a resealed condition.

A blunt cannula, affixed to second fluid flow member, has a fluid flowpath therethrough. The cannula carries a locking member for lockinglyengaging the housing when the cannula extends through the opening of thesealing member. When so positioned, the two fluid flow members areplaced into fluid flow communication.

The locking member can include a luer-type twist lock fitting.Alternately, the locking member can include slidably engageable memberswhich are responsive to axial movement of the injection site and thecannula toward one another.

In accordance with further aspects of this invention, the blunt cannulamay be provided with features that facilitate insertion into theinjection site, enhance fluid flow or dispersion, increase tugresistance, and reduce kickback.

In particular, one embodiment of the cannula includes a tube with aplurality of elongate discharge slots adjacent the distal end. The fluidchanges direction as it passes laterally through the slots and out ofthe tube. The flow area of the slots exceeds the flow area inside thetube. This slot structure enhances fluid flow and dispersioncharacteristics. In addition, the slots decrease the contact surfacearea on the tube exterior so as to facilitate insertion.

In a further modification, the cannula includes a lead post on the tubedistal end to guide the cannula through the slit in the injection site.

In another cannula embodiment, the tube is generally cylindrical and thefluid discharges directly from an open end of the tube. The exteriorsurface of the tube is provided with grooves to reduce the contactsurface area.

In still another cannula embodiment, the tube has a cylindrical portionand a tapered distal end portion which are each about equal in length.The taper facilitates insertion, and the remaining cylindrical portionreduces kickback.

In yet another embodiment, the cannula includes an annular barb whichfunctions to reduce kickback.

Other advantages of a blunt plastic cannula in accordance with theinvention, relative to conventional steel needles include a higher fluidflow rate capacity and a simpler one-piece plastic design.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings in which the details of the invention are fullyand completely disclosed as a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partly in section, of a prior artpre-slit injection site and an associated blunt cannula;

FIG. 2A is a view in perspective of a catheter positioned in the hand ofa patient with a pre-slit injection site in accordance with the presentinvention positioned adjacent thereto;

FIG. 2B is a perspective view of the catheter of FIG. 2A with a pre-slitinjection site in accordance with the present invention rotatablyaffixed thereto;

FIG. 3 is an enlarged side elevational view in a section of a pre-slitinjection site in accordance with the present invention formed on a bodyhaving a luer twist-lock type connector for coupling to a catheter;

FIG. 4A is an exploded view of a pre-slit injection site, a shieldedblunt cannula and a syringe prior to being coupled together;

FIG. 4B is an enlarged, side elevational view in section of the pre-slitinjection site, the shielded blunt cannula and the syringe of FIG. 4Acoupled together to form a sealed fluid flow system;

FIG. 5A is a view in perspective of a pre-slit injection site prior toengaging a blunt cannula carrying a locking member;

FIG. 5B is an enlarged side elevational view, partly broken away,illustrating the interrelationship between the pre-slit injection siteand the blunt cannula of FIG. 5A;

FIG. 6 is an overall view of a container, an associated solutionadministration set and a pre-slit injection site in accordance with thepresent invention;

FIG. 7 is an enlarged side elevational view, partly broken awayillustrating the relationship between selected elements of FIG. 6;

FIG. 8 is a side elevational view, partly broken away illustrating analternate shielded cannula in accordance with the present invention;

FIG. 9 is a side elevational view, partly in section, of a pre-slitinjection site mounted on a fragment of a solution container;

FIG. 10 is a side elevational view of a fragment of a solution containercarrying, as a single port, a pre-slit injection site;

FIG. 11 is a side elevational view of the injection site and thefragmentary container of FIG. 10 prior to being engaged with a shieldedcannula carried by a syringe;

FIG. 12 is an enlarged side elevational view, partly in section, of acoupling system with a pre-slit injection site partly coupled to a bluntcannula;

FIG. 13 is an enlarged side elevational view, partly in section, of thecoupling system of FIG. 12 subsequent to engagement of the two couplingmembers;

FIG. 14 is a side elevational view, partly broken away, of a spikeconnector carrying a pre-slit injection site in accordance with thepresent invention;

FIG. 15 is an enlarged side elevational view of a Y-connector in sectioncarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 16 is an enlarged fragmentary side elevational view in section of acoupling member carrying a pre-slit injection site where the slitextends only partway through the septum;

FIG. 17 is a perspective view of a burette solution administration setcarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 18 is a view of part of a burette solution administration setcarrying a pre-slit injection site being coupled to a shielded bluntcannula;

FIG. 19 is a step in the method of making a pre-slit injection site inaccordance with the present invention;

FIG. 20 is another step in the method of making a pre-slit injectionsite in accordance with the present invention;

FIG. 21 is an initial phase of a final step in making a pre-slitinjection site in accordance with the present invention;

FIG. 22 is an intermediate phase of the final step in a method of makinga pre-slit injection site in accordance with the present invention;

FIG. 23 is a final phase of the final step in a method of making apre-slit injection site in accordance with the present invention;

FIG. 24 illustrates an initial phase in an alternate step of making apre-slit injection site in accordance with the present invention;

FIG. 25 illustrates a final phase of the alternate step in a method ofmaking an injection site in accordance with the present invention;

FIG. 26 illustrates yet another alternate step in a method of making apre-slit injection site in accordance with the present invention;

FIG. 27 is an enlarged, fragmentary cross-sectional view of anotherembodiment of an injection site in accordance with the presentinvention;

FIG. 28 is a cross-sectional view taken generally along the plane 28--28in FIG. 27;

FIG. 29 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 30 is a cross-sectional view taken generally along the plane 30--30in FIG. 29;

FIG. 31 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 32 is a cross-sectional view taken generally along the plane 32--32in FIG. 31;

FIG. 33 is a cross-sectional view taken generally along the plane 33--33in FIG. 32;

FIG. 34 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 35 is a fragmentary, side elevational view of the embodiment of thecannula illustrated in FIG. 34;

FIG. 36 is a cross-sectional view taken generally along the plane 36--36in FIG. 34;

FIG. 37 is a cross-sectional view taken generally along the plane 37--37in FIG. 36;

FIG. 38 is an end view of another embodiment of the cannula according tothe present invention;

FIG. 39 is a cross-sectional view taken generally along the plane 39--39in FIG. 38;

FIG. 40 is a cross-sectional view taken generally along the plane 40--40in FIG. 39;

FIG. 41 is an end view of another embodiment of the cannula according tothe present invention;

FIG. 42 is a cross-sectional view taken generally along the plane 42--42in FIG. 41;

FIG. 43 is an end view of another embodiment of the cannula according tothe present invention; and

FIG. 44 is a cross-sectional view taken generally along the plane 44--44in FIG. 43.

FIG. 45 is a view in section of another insertion member for a bluntcannula.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated.

A prior art pre-slit injection site 10 and associated blunt cannula 12are illustrated in FIG. 1. The prior art injection site 10 has acylindrical housing 14 with a fluid flow path 16 therethrough. A firstend 18 of the housing 14 is closed with a relatively thin disc-shapedresealable member 20. The member 20 has a resealable opening 22 therein.

The member 20 is a molded septum with an integrally formed skirt 20a.The skirt 20a is oriented generally perpendicular to the portion of theseptum with the opening 22.

The cannula 12 includes a body portion 24 which carries at a first end ahollow, cylindrical, blunt piercing member 26. As the cannula 12 ismoved in a direction 28 toward the first end 18 of the injection site10, the member 26 slidably engages the opening 22. The sealing member 20is then deformed adjacent the opening 22 and the member 26 extends intothe flow path 16. A fluid flow path through the cannula 12 will then bein fluid flow communication with the flow path 16 via the hollowpiercing member 26.

In contradistinction to the prior art pre-slit injection site 10 of FIG.1, FIGS. 2A and 2B illustrate a pre-slit injection site 34 being coupledto a peripheral venous catheter 36. The catheter 36 is shown in fluidflow communication with a vein in a hand H of a patient. The catheter 36carries at a proximal end 38 a luer-type female twist lock connector 41.

The pre-slit injection site 34 is formed with a cylindrical housing 40having a first end 42 and a second end 44.

Carried by the housing 40, adjacent the second end 44 is a hollowcylindrical fluid flow member 46. The member 46 slidably engages areceiving member in the housing 38 of the catheter 36, thereby providinga sterile fluid flow coupling as is well known and conventional.

A plurality of internal male luer-type threads 48 is carried by thehousing 40 adjacent the second end 44. The threads 48 will engage theflange member 41 when the injection site 34 is rotated in a direction50. When so coupled together, the catheter 36 and the injection site 40provide a sealed coupling through which fluids may be injected into thevein of the hand H.

FIG. 3 illustrates, in section, further details of the injection site34. A resealable septum 52 is carried by the first end 42 of the housing40. The septum 52 includes first and second spaced apart surfaces 54 and56 respectively. The surface 54 has been forced into a dome-like shapeby annular, U-shaped, swaged end members 58 carried by the first end 42.The dome-like shape of the surface 54 can extend beyond a surface 42a ofthe first end 42. This facilitates cleaning the surface 54.

The septum 52 has a generally cylindrical shape. The septum 52 can beformed of a latex or synthetic rubber material. Alternately, the septumcan be formed of a thermoplastic elastomer. The material used for theseptum 52 should be non-toxic and sterilizable such as by means ofradiation, steam or EtO.

Because the septum 52 is generally cylindrical in shape, it can bedie-cut from a sheet, cut from an extruded rod or molded. The septum 52can have an exemplary diameter on the order of 0.30 inches. The heightof the septum 52 can be, for example, on the order of 0.125 inches.

The first end 42 is also formed with a tapered interior surface 60 whichterminates in an annular channel 62. The tapered interior surface 60 hasa taper in a range of 5 degrees to 20 degrees. Preferably, the taperwill be on the order of 12 degrees. With the indicated size of the abovenoted exemplary septum 52 and a 12 degree taper, diametric resealingcompression of the septum 52 adjacent the channel 62 is on the order of10%.

The channel 62 is bounded in part by a septum supporting ridge 62a. Thechannel 62 can typically have a depth in a range of 0.050-0.070 inches.

A peripheral surface 64 of the septum 52 slidably engages the taperedinterior surface 60 as the septum 52 slides into the first end 42. Theannular channel 62 which underlies the interior peripheral surface 56 ofthe septum 52 is provided to permit the septum 52 to deform when a bluntcannula is inserted through an opening 66 therein.

The housing 40 is also formed with a fluid flow path 68 such that fluidsinjected via a blunt cannula inserted through the resealable opening 66can flow into the catheter 36 for delivery to hand H of the patient.

The swaged end members 58 apply axial forces to the septum 52 therebycreating the domed exterior peripheral surface 54. The axial forcesapplied by the end members 58 slightly deform the regions 52a and 52b.In contradistinction, the tapered internal surface 60 applies radiallydirected forces to the septum 52, thereby forcing the opening 66 into aresealed condition.

As shown in FIG. 3, an axial height of the ridge 62a defines an annularchannel 62b. The region 52a of the septum 52 is partially deformed intothe annular channel 62b by the end member 58 applying axial forces tothe 62b by the end member 58 applying axial forces to the septum 52. Asshown in FIG. 4B. the septum 52 deforms farther into the annular channel62b, and into channel 62, when the blunt piercing member 98 is insertedthrough the opening 66. Referring to FIGS. 19-26, the resealable septumis moveable from a first position contacting the annular ridge andoutside the annular channel prior to compression to a second positioncontacting the annular ridge and extending into the annular channelafter compression.

In an alternate embodiment, the surface 54 could be formed as a flat, asopposed to a domed, surface.

As also shown in FIG. 3, the first surface 54 is proximate the first end42. More particularly, the first surface 54 is proximate an axiallyoutermost portion 42b of the surface 42a. In this manner, the firstsurface 54 can be easily cleaned, i.e. easily wipeable. As discussedabove, the first surface 54 may be dome shaped, and in an alternateembodiment, flat shaped. Also shown in FIG. 3, the first end 42 of theinjection site 34 includes a portion 42c extending from the axialdirection to a radially inward extending portion 42d. The radiallyextending inward portion 42d has a thickness 42e in the axial direction.The thickness 42e is defined in the axial direction at the axiallyoutermost portion 42b of the surface 42a. Accordingly, the first surface54 is a relatively short distance from the axially outermost portion 42bof the surface 42a. In other words, the distance from the axialoutermost portion 42b to at least a portion of the first surface 54 isless than the thickness 42e of the radially inward extending portion42d. Thus, the surface 54 is easily wipeable.

Once the injection site 34 is lockingly engaged with the catheter 36, asealed system is formed through which fluids can be infused into thecatheter 36. The resealable septum 52 closes the fluid flow path 68.

FIGS. 4A and 4B illustrate in combination the injection site 34, a bluntshielded cannula 80 and a syringe of a conventional type 82. The syringe82, as is well known, can be formed with a cylindrical hollow end 84which carries a male luer-type twist lock thread 86. A hollow centrallylocated cylindrical fluid flow member 88 is in fluid flow communicationwith an interior region 90 of the syringe 82.

The shielded blunt cannula 80 carries at a first end 92 a female luertwist-lock flange 94. The flange 94 will slidably engage the threads 86of the end 84. Hence, the shielded blunt cannula 80 can be locked to thesyringe 82 forming a closed fluid flow pathway. The shielded cannula 80could alternately be formed fixedly attached to the syringe 82.

The shielded blunt cannula 80 carries a cylindrical hollow protectiveshield 96 which surrounds a centrally located hollow, elongatedcylindrical blunt piercing member 98. The cylindrical blunt piercingmember 98 has a total length on the order of 3 times the thickness ofthe septum 52 in order to ensure complete penetration. The cylindricalblunt piercing member 98 has a diameter on the order of 1/3 the diameterof the septum 52. The shield 96 is desirable and useful for maintainingthe piercing member 98 in an aseptic condition by preventing touchcontamination prior to the shielded cannula 80 engaging the pre-slitseptum 52. Also, the shield helps to align the piercing member with thepre-slit septum.

The cylindrical blunt piercing member 98 can slidably engage thepre-slit septum 52, best illustrated in FIG. 4B, thereby extendingthrough the preformed opening 66 therein. As illustrated in FIG. 4B,when the piercing member 98 slidably engages and pierces the septum 52,the region 52a deforms by expanding into and filling, at least in part,the annular channel 62.

As can be seen in a comparison between FIGS. 3 and 4B, the resealableseptum 52 has a sealing surface 66a defined by the resealable opening66. The sealing surface 66a extends in an axial direction prior toinsertion of the blunt piercing member 98 through the septum 52 andremains in the axial direction after insertion of the piercing member 98through the septum 52. As shown in FIG. 4B, the axial length of thesealing surface 66a of the resealable opening 66 increases when thepiercing member 98 is inserted through the septum 52.

The deformation facilitates insertion of the piercing member 98 throughthe slit 66. Subsequent to the piercing member 98 slidably engaging theinjection site 34, the interior region 90 of the syringe 82 is in fluidflow communication with the flow path 68 of the injection site 34 viaflow paths 88a and 99 respectively of the syringe and the blunt piercingmember 98.

In this engagement condition, the septum 52 seals completely around thepiercing member 98. Hence, exterior gases, liquids or airborne matterwill be excluded from the channel 68.

Subsequent to infusing fluid from the syringe 82 into the fluid flowpathway 68, hence into the catheter 36 and the hand H of the patient,the syringe 82 with lockingly engaged shielded cannula 80 can beslidably withdrawn from the injection site 34. Subsequent to thiswithdrawal, the septum 52 reseals the opening 66 therein.

The opening 66 will repeatedly reseal, when the piercing member 98 isremoved, provided that the pressure (in the septum 52 of the opening 66)created by interaction of the septum material properties and compressionsupplied by the housing exceeds the pressure challenge of the fluidcontained within. Blunt cannula do not haphazardly core, lacerate, orotherwise damage the sealing interface 66 as conventional needles do,thereby allowing repeatable resealability. However, septum materialproperties, thickness, and compression allow resealability for a finitenumber of conventional needle insertions. The combination injection site34 and catheter 36 then return to its pre-infusion, sealed condition.

FIGS. 5A and 5B illustrate the pre-slit injection site 34 used incombination with a blunt cannula 80a. The cannula 80a includes a hollowbody portion 92a with a Luer flange 94a, a piercing member 98a, andmanually operable elongated locking members 100a and 100b. Alternately,a tubing member could be affixed to the hollow body portion 92.

Curved end regions 100c of the members 100a and 100b slidably engage thesecond end 44 of the housing 40 when the piercing member 98a of theblunt cannula 80a has been forced through the pre-formed opening 66,best illustrated in FIG. 5B. The embodiment illustrated in FIGS. 5A and5B has the advantage that the infusing cannula 80a cannot accidentallydisengage from the pre-slit septum 34 during the fluid infusion process.It will be understood that while spring-like deflecting members 100a and100b are illustrated in FIGS. 5A and 5B that other forms of lockingmembers are within the spirit and scope of the present invention.

FIG. 6 illustrates an alternate pre-slit injection site 34a. A tubingmember 102 can be fixedly attached to the cylindrical hollow fluid flowmember 46. The embodiment 34a of FIG. 6 utilizes the same structure forthe septum 52 including the tapered surface 60 and the underlyingannular channel 62 as does the embodiment 34 in FIG. 3. The shieldedcannula 80 can be utilized with the injection site 34a as previouslydescribed.

In the event that it is desirable to infuse solution from a container104 with a conventional port 106, a fluid administration set 110 of aconventional variety may be utilized. The set 110 includes a spikeconnector 112 at a first end. The spike connector 112 is designed topierce the port 106 of the container 104. The set 110 can also carry aslidably engageable connector 114 of a known type at a second end. Asillustrated in FIG. 7, the connector 114 can slidably engage the firstend member 92 of the shielded cannula 80, thereby placing the interiorfluid of the container 104 into fluid communication with the tubingmember 102.

FIG. 8 illustrates yet another alternate 80b to the shielded cannula 80.The piercing member 98b carries a tubing member 118 fixedly attachedthereto. The tubing member 118 could be coupled at a second end to acontainer such as the container 104.

The present pre-slit injection site can be directly affixed to acontainer 120 as illustrated in FIG. 9. The container 120 includes arigid hollow cylindrical access port 122 affixed thereto. The accessport 122 includes a fluid flow channel 124 in fluid flow communicationwith the interior of the container 120. Sealingly affixed to the port122 is a pre-slit injection site 126.

The site 126 includes a cylindrical housing 128 which carries at a firstend 130 a septum 132 with a slit 134 formed therein. The first end 130has been swaged to form an annular U-shaped retaining member 136. Theretaining member 136 in turn forms a domed exterior peripheral surface138 on the septum 132.

The first end 130 also includes a tapered interior force applyingsurface 140 and an annular channel 142 underlying the septum 132. Asdiscussed previously, the channel 142 provides a space into which theseptum 132 can deform when a blunt cannula is forced through theresealable opening 134.

Further, as illustrated in FIG. 9, the injection site 126 can be coveredby a removable cover 146 of a type used with the conventional port 106of the bag 120.

While the bag 120 is illustrated formed with two ports, the conventionalpierceable port 106 and the pre-slit injection site 126, it will beunderstood that as an alternate (FIG. 10), a container 150 could beformed which includes only the pre-slit injection port 126. Theremovable cover 146 could be used in combination with the container 150.

As illustrated in FIG. 11, the pre-slit injection site 126 can beutilized for the purpose of injecting fluid from the syringe 82, coupledto the shielded cannula 80, into the container 150. When so utilized,the blunt piercing member 98 is used to place the interior fluidcontaining region 90 of the syringe into fluid flow communication withthe interior of the container 150.

FIGS. 12 and 13 illustrate a fluid flow coupling system 151 having as afirst element a pre-slit injection site 126a. The site 126a is the sameas the site 126 except for a plurality of exterior threads 153 formed onan exterior peripheral surface 155 of the housing 128a. A second elementof the coupling system 151 is a shielded blunt cannula 157.

The shielded blunt cannula 157 is sealingly affixed to a flexible tubingmember 159 by means of a proximal hollow cylindrical member 161. Themember 161 extends into a hollow cylindrical shield 163 to form a bluntpiercing member 165.

The shield 163 carries, on an interior peripheral surface, a set ofcoupling threads 149. The threads 149 match the threads 153.

The two connector elements 126a and 157 slidably engage one another whenthe shielded cannula 157 moves in an axial direction 167 toward theinjection site 126a. The blunt piercing member 165 penetrates the septum132a.

The coupling member 157 can then be rotated in a direction 169 such theinterior set of threads 149 carried thereon engages the exterior set ofthreads 153. As a result, the two coupling members 126a and 157 arelockingly engaged together with the insertion member 165 extendingthrough the opening 134a in the septum 132a. Hence, fluids can flow fromthe container 150a via the connector system 126a and 157 through thetubing member 159 to the recipient.

Injection sites of the type described above are also usable inconnection with other fluid flow coupling components. For example, withrespect to FIG. 14, a pre-slit injection site 160 of the type describedabove can be used in combination with a spike connector 162 of aconventional variety. Spike connectors such as the spike connector 162can be used to pierce conventional ports such as the port 106 of thecontainer 104 (FIG. 6). When the spike connector 162 is so used, thepre-slit injection site 160 can then be utilized for the purpose ofcoupling to other fluid administration sets.

The injection site 160 illustrates an alternate form of swaging thefirst end 42c for the purpose of retaining the septum 52c therein. Thefirst end 42c can be swaged so as to form an annularly shaped, spiral,spring-like member 164. The member 164 has a free end 164a which engagesthe exterior dome-shaped peripheral surface 54c of the septum 52c. Thespiral, spring-like swaged member 164 will tend to uncoil, therebycontinuously applying axial force to the septum 52c and maintaining thedomed exterior peripheral surface 54c.

In yet another alternate, FIG. 15 illustrates a pre-slit injection site166 formed in a Y-junction member 168. The Y-junction member 168 isfixedly attached to first and second tubing members 170 and 172respectively.

As an alternate to forming the slit 66 completely through the septum 52,as illustrated in FIG. 16, a slit 66e can be formed only partly throughthe septum 52e. Such a structure has the further advantage that, untilused for the first time, the septum 52e is completely sealed.

The septum 52 can be formed in two parts. One part can have a slit, suchas the slit 66, extending entirely therethrough. A second part can beformed without a slit. These two parts can be located adjacent oneanother in the first end 42 of the injection site.

The slit 66 may be longer on the top of the septum than the bottom. Thisfeature aids blunt cannula alignment with the slit upon insertion, andaids resealability by minimizing the critical slit sealing interfacearea.

In accordance with the present invention, the slit could have a lengthwith a range on the order of 0.03 to 0.150 inches. Preferably, a slitlength on the order of 0.07 inches will be used in combination with ablunt cannula having a diameter on the order of 0.1 inches.

When initially used, the blunt cannula piercing member, such as themember 98, will be forced through the slit 66a. The lower peripheralsurface 56e will then be punctured, providing access for the bluntcannula piercing member 98 into the fluid flow pathway 68e.

Pre-slit injection sites of the type described above can be utilized incombination with burette solution administration sets. One such set 176is illustrated in FIG. 17. The set 176 includes a pre-slit injectionsite 178 of the type described above. The injection site 178 is affixedto an exterior planar surface 180 of the burette 182. A removable cover184 can be used to maintain the injection site 178 in an asepticcondition until blunt cannula 186 or 188 is inserted therethrough.

FIGS. 19-23 disclose a method of making a pre-slit injection site inaccordance with the present invention. In a first step, a housing 200 isprovided. The housing 200 has an interior tapered surface 202 at a firstend 200a thereof. The interior peripheral surface terminates in anannular channel 204. A cylindrical septum 206 can be provided adjacentthe end 200a.

In a second step, the septum 206 can be forced into the end 200a of thehousing 200 and slightly deformed by the tapered peripheral surface 202using an axially moving die 210. When positioned by the die 210, theseptum 206 is located adjacent an internal annular ring 212 which boundsthe annular channel 204.

In a third step, a second die 214 can be utilized to swage the end 200ainto spiral-shaped, spring-like members 200b which apply axiallydirected forces against an exterior peripheral surface 206a of theseptum 206. The axially directed forces form the flat surface 206a intoa domed exterior peripheral surface 206b as illustrated in FIG. 23.

Simultaneously, with swaging the end members 200a so as to lock theseptum 206 into the housing 200 and to form the domed exteriorperipheral surface 206b, a knife 216 can be utilized to form a slit inthe septum 206. Alternatively, the slit may be cut by a separate die ina separate step. If the septum 206 is formed as an extrusion, the slitcan be created during the extrusion process. If the septum 206 is formedby stamping from a rubber sheet, the slit can be cut during the stampingprocess. If the septum 206 is formed by compression molding, the slitcan be cut during the trimming process.

In order to extrude the slit into rod, a flat pin extrusion bushing canbe used. A trailing ribbon may be attached to the bushing. The ribbonwould prevent curing material across the slit. The ribbon or wire couldbe placed in the rod core and later stripped out leaving a slit. Aninert substance, such as silicone oil, could be coextruded in the centerof the rod to prevent curing across the slit and provide lubrication anda visible target for cannula insertion.

FIGS. 24 and 25 illustrate alternate swaging steps wherein a die 220moving axially toward the housing 200 swages the end region 200a so asto form an annular U-shaped region 200c and the exterior domedperipheral surface 206c.

The dies 214 or 220 can be formed with various alternate shaped swagingsurfaces 224, as illustrated in FIG. 26, depending on the precise shapeof the end swage which is desired. It will be understood that all suchvariations in the swaging operation are within the spirit and scope ofthe present invention.

The injection site configuration need not be limited to theconfigurations depicted in FIGS. 3-5B, 9, 12-16. Rather, severalconfigurations could be constructed without departing from the scope ofthis invention. Any such configuration would provide a flexible preslitsealing member captured in a housing which provides compression tocreate a seal against pressure and a void region to accommodate deformedportions of the sealing member material only when the material isdeformed or displaced by a blunt cannula piercing member. One suchpossible configuration is depicted in FIGS. 27 and 28.

FIGS. 29 and 30 illustrate a tapered cannula structure 250 which is analternate to the tapered cannula 98. The cannula 250 includes a proximalend 252 with an interior region 254. The region 254 is in part boundedby an internal peripheral wall 256 which is formed with a standard Luertaper. The tapered cannula 250 can be formed with a Luer-type couplingflange 257 at the proximal end so as to be releasably connectable to thesyringe 82 as was the tapered cannula 98 previously discussed.

Extending from the proximal end 252 is a cylindrical tube having acylindrical mid-region 258 and a distal end member 260. The member 260has a generally elongated, cylindrical shape with an exterior side wall262. A centrally located, cylindrical, internal fluid flow path 264extends through the distal end member 260 and mid-region 258 in fluidflow communication with the interior region 254.

The distal end of the end member 260 has a tapered exterior surface 266.The tapered exterior surface 266 minimizes insertion force as thecannula 250 is being forced through a slit of a septum, such as the slit66 in the septum 52. The angle of taper of the surface 266 is preferablyin a range between 25 to 45 degrees.

The member 260 is also provided with a plurality of elongated grooves268. The grooves 268 in the exterior wall of the member 260 decrease thesurface area of contact at the cannula/septum interface during insertionof the cannula into the injection site 34. This reduced exterior contactsurface area decreases the frictional component of the insertion force.

In one embodiment, the tapered blunt cannula 250 may have overallinsertion length, corresponding to combined axial lengths of mid-region258 and end member 260, on the order of 0.375 inches.

An alternate cannula structure 280 is illustrated in FIGS. 31, 32 and33. The cannula structure 280 includes a proximal end region 282corresponding to the end region 252 of the cannula 250. The region 282includes a Luer flange 283. The cannula 280 also includes a central,elongated, cylindrical region 288.

The central region 288 carries at a distal end thereof an elongatedcylindrical end member 290. The member 290 includes an exterior,peripheral, cylindrical surface 292 (FIG. 31). The surface 292 isinterrupted by a plurality of spaced-apart, elongated slots or apertures294. The slots 294 are defined by first and second spaced-apart,elongated, parallel side surfaces 294a and 294b. Each of the slotsterminates in an end surface 294c at the central region 288.

A fluid flow path 294d extends through the cannula 280. The flow path294d is in fluid flow communication with the slots 294.

Between the slots 294, at a distal end of the region 290, the exteriorsurface 292 terminates in tapered end regions 298 to facilitateinsertion of the cannula into a pre-slit injection site. The slots 294themselves also function to decrease the surface contact area, and thisfurther minimizes the insertion force.

The slots 294 are oriented substantially 90 degrees apart around alongitudinal axis 300. The slots 294 increase the internal flow pathcross-section. This increases the fluid flow rate.

The slots 294 also provide for enhanced dispersion characteristics owingto the fluid flowing radially out through the slots 294. This radialflow, effecting a change in fluid flow direction of about 90 degrees,promotes flushing and dispersion of fluid through the injection site 34.

Another embodiment of a blunt cannula 310 is illustrated in FIGS. 34-37.The cannula 310 is formed with an enlarged proximal connection region312 corresponding to the region 252 of the cannula 250. The region 312includes a Luer flange 313 and a central fluid flow region 314.

An intermediate, cylindrical region 318 extends from the proximalconnection region 312. The cylindrical intermediate region 318 includesa fluid flow path 320 in communication with the fluid flow region 314.

The end region 324 extends from the region 318 and includes a firstcylindrical portion 326 into which the fluid flow path 320 extends. Theregion 326 terminates in a tapered exterior surface 328. The taperedexterior surface 328 merges with a centrally located lead post or guidepost 330. The lead post 330 terminates in a hemispherical end surface332.

The lead post 330 helps locate the septum slit 66 prior to insertion andfacilitates penetration of the septum slit 66 by the cannula. The leadpost 330 facilitates insertion by providing a very low insertion forceat the beginning of the insertion step as the cannula is pushed throughthe slit, such as the slit 66.

In a preferred embodiment, the guide post 330 can have a length on theorder of 0.060 inches and a diameter on the order of 0.050 inches.

The end region 318 includes a novel structure for increasing the flowrate and enhancing dispersion characteristics. In particular, the region318 includes three radially oriented slots 338. Each slot 338 has sides339a and 339b which each lie along a radius of the cylindrical portion326 as best illustrated in FIG. 37. The fluid flowing through thecannula 310 undergoes a change in direction (of up to about 90 degreesrelative to the cannula center line 337) in the slots 338. This changein direction increases fluid dispersion. Further, since the slots 338open radially, fluid flow can be maintained even if the end surface 332of the cannula is pushed up against any material in the system in whichthe cannula is inserted.

Another embodiment of the tapered cannula of the present invention isillustrated in FIGS. 38-40 and is designated generally therein byreference numeral 340. The cannula 340 includes a proximal end 342 whichcan include a Luer coupling flange 344 for cooperating with a suitablemating structure on a syringe. The proximal end 342 also defines aninterior region 346.

Extending from the proximal end 342 is a generally cylindricalmid-region 348. Extending from the mid-region 348 is an end member orregion 350 which includes a tapered surface 352.

The distal end of the end region 352 terminates in a blunt, arcuate endsurface 356. Defined within the mid-region 348 and end region 350 is aninternal fluid flow channel 354 which communicates with the interiorregion 346. Fluid discharges from the flow channel 354 via grooves orapertures 358 in the end region 350. The change in direction of thefluid flow as the fluid passes from the interior channel 354 through theapertures 358 improves fluid dispersion with respect to mixing orflushing in the system downstream of the cannula (e.g., the injectionsite, drug vial, etc.). The apertures 358 may also function to increasewithdrawal force or tug resistance.

Moreover, since the fluid passes radially out through the apertures 358,fluid flow through the cannula 340 can be maintained even when thedistal end surface 356 of the cannula is bottomed out or pushed againstany material in the system in which the cannula is inserted.

The structure of the cannula 340 is adapted to be constructed with aminimal lead post length (i.e., the portion of the cannula distal endbetween the end surface 356 and the interior flow channel 354). Further,the design accommodates the use of a minimal tip diameter, minimal taperangle, and minimal cannula diameter. The minimization of theseparameters results in a decrease in the peak insertion force required toproperly install the cannula in the injection site.

Preferably, the total cross-sectional flow area through the threeapertures 358 is about three times the cross-sectional flow area of theinterior channel 354. This enhances the flow rate capability comparedwith a simple open ended cylindrical flow channel of equal length.

The design of the cannula 340 also is effective in reducing or limiting"kick back" or recoil of the cannula after insertion. The resilientmaterial of the septum in an injection site can subject the cannula toforces tending to push the cannula back out of the septum. The kick backforces on the cannula 340 are minimized by the provision of thegenerally cylindrical mid-region 348.

Another embodiment of the cannula of the present invention isillustrated in FIGS. 41 and 42 wherein the cannula embodiment isdesignated generally therein by the reference numeral 360. The cannula360 includes a proximal end 362 defining an interior region 364 andhaving a Luer flange 366 for connection to a suitable mating engagingstructure.

A generally cylindrical mid-region 366 extends from the proximal end362, and a end region 368 extends from the mid-region 366. As with theprevious embodiment of the cannula 340 illustrated in FIGS. 38-40, theembodiment of the cannula 360 minimizes kick back or recoil owing to theprovision of a substantially cylindrical mid-region 366. This designalso increases withdrawal or tug resistance.

A generally cylindrical internal flow channel 370 extends through theend region 368 and mid-region 366 in communication with the interiorregion 364 of the proximal end region 362. The end region 368 isprovided with a tapered surface 372. The design permits the use of avery small taper to minimize the insertion force.

Further, the design permits the cannula 360 to be constructed with asmall tip diameter, small taper angle, and small cannula diameter so asto reduce the peak insertion force.

Another embodiment of the cannula of the present invention isillustrated in FIGS. 43-44 and is designated generally therein byreference numeral 380. The cannula 380 includes a proximal end 382 witha Luer flange 384. An interior fluid flow region 386 is defined on theinterior of the proximal end 382.

Extending from the proximal end 382 is a mid-region 388. A distal endregion 390 extends from the mid-region 388. An internal fluid flowchannel or path 392 extends through the end region 390 and mid-region388, and is in communication with the interior flow region 386.

The end region 390 has an exterior tapered surface 394. This facilitatesinsertion of the cannula into the injection site. In contrast, themid-region 388 is generally cylindrical so as to minimize kick back andincrease the withdrawal force or tug resistance.

Further, to provide even greater withdrawal force, the mid-region 388includes an annular barb 396. The barb 396 has a sufficient radius so asto preclude damage to the septum of the injection site and so as toaccommodate molding in a straight-draw tool. The maximum diameter of theannular barb 396 may typically be on the order of 0.02 inches greaterthan the diameter of the cylindrical mid-region 388. Although the barb396 functions to prevent inadvertent removal of the cannula 380 from theseptum of the injection site, removal of the cannula 380 can still beachieved by exerting a sufficiently great axially directed removal forceon the cannula 380.

Still another embodiment is illustrated in FIG. 45 which includes ablunt tapered cannula insertion member 400 for insertion into a pre-slitinjection site, the cannula 400 having a distal end region 402 with atapered exterior surface which in the preferred embodiment is anapproximately 8° taper. The defined aperture 404 for fluid flow isdisposed at the end 406 of the distal end region 402. The end 406includes a radiused tip defined by a radius of approximately 0.01 inch.The radiused tip reduces insertion force, assists in locating the slitin the injection site and in addition has the practical advantage offacilitating complete filling of the cannula mold cavity.

The tapered surface of the distal end region 402 has an axial length ofapproximately 0.10" in the preferred embodiment. Adjacent to the tapereddistal end region is a generally cylindrical region 408 for enteringinto the injection site behind the distal end region 402, therebyreducing kick back during insertion. The generally cylindrical region408 has a small draft angle such as about one-half degree.

The force required to insert any of the above-discussed embodiments ofthe blunt tapered cannula into the septum of the injection site dependsupon a number of factors: friction at the cannula/septum interface,cannula diameter, cannula taper angle, and degree of septum compression.The cannula/septum interface friction is, in turn, dependent uponlubrication, if any, material properties, and surface finish. It will beunderstood that the friction at the cannula/septum interface can bereduced by providing a smoother surface finish on the cannula (e.g., bysand blasting the cannula exterior surface) or by molding the cannula soas to produce a matte finish. Conventional lubricants can also be usedto further reduce the friction and thereby lower the insertion forcerequired.

In the embodiments of the cannulae described herein, the mid-region andthe tapered distal end region may be alternatively characterized astogether forming at least one tube defining a fluid flow path thereinwith the tube having a distal end region for penetrating the injectionsite.

In preferred contemplated embodiments, the exterior surface of thedistal end region may have a taper angle as small as between one andfifteen degrees.

Further, a locking means, such as the locking arms 100a, 100b discussedwith reference to FIGS. 5A and 5B, may be provided on the cannulaembodiments illustrated in FIGS. 29-45 to permit the cannulae to bereleasably locked to the injection site.

The above described insertion members, usable as part of a bluntcannula, are preferably molded of a plastic formulation includingsilicone or other lubricant. The use of silicone or other lubricantincreases the ease of insertion of that member into the pre-slitinjection site.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the novel concept of the invention. It is to be understood thatno limitation with respect to the specific apparatus illustrated hereinis intended or should be inferred. It is, of course, intended to coverby the appended claims all such modifications as fall within the scopeof the claims.

What is claimed is:
 1. A cannula and injection site in combinationcomprising:an injection site having a housing defining a fluid flow paththerein and having a penetrable sealing means for sealing said housing;a cannula having at least one tube defining a fluid flow path therein,said tube extending through said sealing means to establish a sealedfluid flow connection with said injection site, said tube having adistal end region extending beyond said injection site and having atapered surface on said distal end region; and said tube defining insaid distal end region a plurality of elongate slots oriented parallelto said fluid flow path, each slot extending from said flow path to theexterior of said tube thereby decreasing the exterior contact surfacearea of said tube and accommodating a lateral discharge of fluid fromsaid tube.
 2. An injection site adapted for use with a blunt cannulacomprising:a pre-slit septum axially compressed within a housing andhaving an easily wipeable outer surface, the septum having a sufficientthickness to seal completely around the blunt cannula upon insertion;the housing having an end circumjacent the septum, the end having aportion that extends radially inward and applies an axial compressiveforce to the septum; and, a luer-type fitting carried by the housing ata housing end opposite the septum.
 3. The injection site of claim 2wherein the portion forms a radiused corner.
 4. The injection site ofclaim 2 wherein the easily wipeable outer surface is dome shaped.
 5. Theinjection site of claim 2 wherein the easily wipeable outer surface issubstantially flat.
 6. The injection site of claim 2 wherein the portionof the end of the housing comprises a radially inward extending portionhaving a thickness in the axial direction, and wherein a distance froman axial outermost portion of the end of the housing to at least aportion of the easily wipeable outer surface is less than the thicknessof the radially inward extending portion.
 7. The injection site of claim6 wherein the easily wipeable outer surface is dome shaped.
 8. Theinjection site of claim 6 wherein the easily wipeable outer surface issubstantially flat.
 9. The injection site of claim 2 wherein a thickestportion of the septum in the axial direction comprises a resealableopening.
 10. The injection site of claim 2 wherein the septum has aresealable opening and the septum is in fluid sealing contact with theblunt cannula along substantially an entire length of the resealableopening when the blunt cannula is inserted through the septum.
 11. Aninjection site adapted to be used with a blunt cannula comprising:ahousing defining a fluid flow channel therethrough, the housing having afirst end and a second end; a resilient sealing member, carried by thehousing overlying the channel for sealing the first end, the sealingmember being formed with a resealable opening therein extending at leastpartway therethrough and having an exterior peripheral surface, thesealing member having a thickness that is sufficient to seal completelyaround the blunt cannula upon insertion; the housing having an endcircumjacent the exterior peripheral surface, the end having a portionthat extends radially inward and applies an axial compressive force tothe sealing member which generates resealing radial forces to urge theresealable opening into a closed condition; a slidably engageableconnector member at the second end and in fluid communication with theflow channel; and, a threaded connector carried by the housing at thesecond end, the threaded connector being spaced radially outward fromthe slidably engageable connector member.
 12. The injection site ofclaim 11 wherein the portion of the end of the housing extends from anaxial direction to a radially inward direction.
 13. An injection siteadapted for use with a blunt cannula comprising:a housing defining afluid flow path through the housing; and, a resealable septum containedwithin the housing and fluidly sealing the fluid flow path, the septumhaving a resealable opening having an axial length through the septum,wherein the septum is capable of maintaining fluid sealing contact withthe blunt cannula along substantially the entire axial length of theresealable opening when the blunt cannula is inserted through theseptum.
 14. The injection site of claim 13 wherein the septum has asealing surface defined by the resealable opening, the sealing surfaceextends in an axial direction prior to insertion of the blunt cannulathrough the septum and remains in the axial direction after insertion ofthe blunt cannula through the septum.
 15. The injection site of claim 13wherein the axial length of the resealable opening increases when thecannula is inserted through the septum.
 16. The injection site of claim13 wherein the septum further comprises an easily wipeable outer surfaceproximate an axially outermost portion of a housing end.
 17. Theinjection site of claim 16 wherein the axially outermost portion of thehousing end comprises a radially inward extending portion having athickness in the axial direction, and wherein a distance from an axiallyoutermost surface of the radially inward extending portion to the easilywipeable outer surface is less than the thickness of the radially inwardextending portion.
 18. The injection site of claim 17 wherein the easilywipeable outer surface is dome shaped.
 19. The injection site of claim17 wherein the easily wipeable outer surface is substantially flat. 20.The injection site of claim 13 wherein the housing further comprises anend circumjacent the septum, the end having a portion that extendsradially inward and applies an axial compressive force to the septum.21. The injection site of claim 20 wherein the portion forms a radiusedcorner.
 22. An injection site adapted for use with a blunt cannulacomprising:a housing defining a fluid flow path through the housing; apre-slit, resealable septum contained within the housing and fluidlysealing the fluid flow path, the septum having an easily wipeable outersurface proximate an axially outermost portion of a housing end; and, ahousing end opposite the septum carrying a fluid coupling.
 23. Theinjection site of claim 22 wherein the easily wipeable outer surface isdome shaped.
 24. The injection site of claim 22 wherein the easilywipeable outer surface is substantially flat.
 25. The injection site ofclaim 22 wherein the housing end comprises a radially extending inwardportion that applies an axially compressive force to the septum, theradially extending inward portion having a thickness in the axialdirection, andwherein a distance from the axially outermost portion ofthe housing end to the easily wipeable outer surface is less than thethickness of the radially extending inward portion.
 26. The injectionsite of claim 22 wherein the fluid coupling comprises a luer-typefitting.
 27. An injection site for use with a blunt cannula comprising:ahousing having an annular ridge which defines an annular channel, theannular channel positioned radially outward from and adjacent to theannular ridge, the annular channel and the annular ridge havingsubstantially equal axial heights; and, a pre-slit septum axiallycompressed between a housing end and the annular ridge, wherein theseptum is moveable from a first position contacting the annular ridgeand outside the annular channel prior to compression to a secondposition contacting the annular ridge and extending into the annularchannel after compression.
 28. The injection site of claim 27 whereinthe septum moves from the second position farther into the annularchannel when the blunt cannula is inserted through the septum.